Can a master summoner use this book since it has nothing to do with changing out the Spell slots Mike other rods or feats? Seemed pretty harmless.
will only work on his spells that summon, not spell like abilities .
from the book's info:
"The user may apply the Extend Spell feat to these spells as they are cast" - you can't apply metamagic feats to sla. also it say to work like metamagic rods. those also say they can't be used with sla.